Printing-telegraph system.



C. G. ASHLEY.

PRINTING TELEGRAPH SYSTEM.

APPLIQATION FILED MAY 11. 1911.

Patented May 5, 1914 2 SHEETS-SHEET 1.

INVENTQR, @I MW 1%.@

COLUMBIA PLANOGRAPH co.. WASHINGIGN. D. c;

C. G. ASHLEY.

PRINTING TBLBGRAPH SYSTEM.

APPLIOATIQ 111111111111111 1.

" Breit. f

CHARLES G'. ASHLEY, OF CHICAGO, ILLINOIS, ASSIGNOR TO GENERALENGINEERING AND CONSTRUCTION COMPANY, LIMITED,

OF TORONTO, CANADA, A CORPORATION.

PRINTING-TELEGRAPH SYSTEM.

T0 all 'whom t may concern.'

Be it known that I, CHARLES G. ASHLEY, a citizen of the United States ofAmerica, and a resident of Chicago, county of Cook, and .State ofIllinois, have invented a new and useful Improvementl inPrinting-Telegraph Systems, of which the following is a specification.

lily invention pertains to automatic printing telegraph systems of theclass employing a plurality of component printing elements or types, thecomplete legible characters being formed of impressions in properrelation and sequence from a plurality of the component typesrepresenting the various component parts of the characters to berecorded.

In an application filed by me on February 6th, 1911, Serial No. 606784,I have disclosed a system of printing telegra-phy in which a pluralityof printing elements are electromagnetically operated over one of a pairof line conductors and ground to make con-1 tact with a record sheet,while the recording of an impression of any element of the group isselectively controlled over the remaining line conductor and ground.Thus current impulses of variant polarity over one line conductor andground operate the printing elements to make Contact in predeterminedgroups with a record sheet, while current impulses of 'variant polarityover the other line conductor and ground cause the selective imprintingof any printing element of a group in contact with the recording sheet.

It is with a view toward simplifying the system and decreasing theinstallation cost that my present invention is directed. I accomplishthis and other desirable features which will be subsequently hereindisclosed by a novel arrangement of apparatus and circuits which enablesme to transmit intelligence. and record the same in the Roman alphabetby the use of but a single line conductor.

In the figures which accompany and form a part of this specification andin which like numerals designate corresponding parts throughout, Figure1 illustrates in diagram the apparatus and circuits at both atransmit-ting and receiving station, together with the line conductor.connecting them. Fig. 2 is a plan view of the under side of one portionof the receiving apparatus of my improved system. Fig. 3 is a magnifiedView of the monogram or the impressions of the Specication of LettersPatent.

Application filed. May 11, 1911.

Patented May 5, 1914.

serial No. 626,427.

printing type elements as they would appear were all of the typesimprinted on a stationary recording surface. Fig. l shows a section oftransmitting tape perforated with all the combinations of perforationsnecessary to transmit all of the characters of the ltoman alphabet, andthe numerals from O to 9. Fig. 5 shows graphically the periodicity ofthe voltage of the current used to effect the selection of the imprintsof the type faces and is so placed with relation to Fig. 4 as to clearlydisclose the time relation existing between the magnet selectioncurrents and the imprint selection currents. Fig. 6 illustrates asectional transmitting tape perforated to form all of the charactersnecessary to transmit intelligence in the Roman alphabet with myimproved system, and also shows the character and outline of the lettersand numerals as recorded by my improved receiving device.

Referring to Figs. 1 and 2, the receiving device of my improved systemis shown in diagram at the left of Fig. 1 and comprises a permanentpolarizing magnet 9 of substantially rectangular form7 within which ismounted an electromagnet 10, presenting a pole face, substantiallymidway between the poles of the polarizing magnet 9. An arma- .ture 12is placed opposite the free pole of electro-magnet 10 and between thepoles of the polarizing magnet 9. This armature is pivoted at itscentral portion between two non-magnetic journal plates 13 and 14: bymeans of the trunnion screws 5 and 6. Strips of ivory or otherinsulating material,

.121 and 122 are rigidly attached to the under portion Vof the armature12, near its outer extremities. These insulating strips normally restlightly against four light nonmagnetio springs 1, 2, 3, and e, which arerigidly attached at one extremity to the polarizing magnet 9 andareinsulated therefrom and from each other by means of the insulatingblocks 7 and 8.' Each spring bears on its free extremity an ironprinting element or type face 11 22 32 and 4:4. The springs with theirrespective type face will be hereafter referred to as printing pens.

The springs bearing elements 11 and 22 are connected together as are thesprings bearing elements 33 and 44. A platinum surfaced anvil 11 isplaced opposite the printing elements 11, 22, 32 and 41:2V and isadjustable in its distance therefrom by means of the screw as indicated.tape sensitized with any ot the u'ell known chemical compoundsI vtorelectrolytic printing, such as a mixture oft nitrate oi ammonium,chlorid of amnumiuiu and red prussiate ot potassium, rest., on thesurface of the anvil in a position to receive impressions from any oneof the printing type faces. rlhe printing pens 1.l i?, 3 and el arenormally held out of contact with the receiving tape 11l through theirinherent spring tension, which causes them norma .y to inno a relaxedposition and hear lightly against the insulating' strips 121 and 122 otarmature 12, thus tending' to aid the polarizing magnet J to maintainarmature 12 normally in a substantially horizontal position when magnet10 is deonergized.

jin elcctromagnetioally polarized relay 100 comprising the operatingelectromagnets 1.3 and 16, polarizing electromagnet- 18, armature 17 andcontacts 25 and 26, has the windings of .its operating magnets and lf3so placed with relation to each other that a` current impulse throughthe windings in series `induces unlike poles on the opposed or operatingextremities of the cores, While current impulse through the windings ina direction opposite from that otl the first impulse rercrses therespective polarity of the pole faces. The windings ot' electromagnets15 and 1G and the Winding ot electromagnet 10 arc connected in seriesbetween the line conductor 29 and ground 28. A pair of batteries 21 and22, or equivalentI sources of current, have their terminals of oppositepolarity connected together and through an adjustable resistance withone terminal of the polarizing magnet 18 of relay 100, the otherextremity of which is connected to armature 17; and also through 2O and1S and a resistance 19 and conductor 24 With one of the blades of adouble pole, double tarow knife switch 42, the other blade 01:' which isconnected through conductor 28 with the conductor joining the oppositeterminals of batteries 21 and 22. @ne terminal o3t` a pair of terminalsof knife switch 4152 is connected to the conductor joining` printingpeus 3 and ai., While the other terminal ot' the pair is connected tothe conductor joining printing pens 1 and 2. The pairs of printing pens1, 2 and 3, ai are connected to the second pair of terminals of knifeswitch #i2 in re'i'erse order from their connection to the first pair ofterminals by means of the crossed jumper Wires on the switch 4Q asindicated.

Referring now especially to relay 100, it will be obserif'ed that if thearmature 17 is in contact with contact 25 current Will flow :frombattery 21 through contact 25, armature 17 and thence through the helixof,

y clectroniagnet 1S to the negative pole of i @D battery 2.1, to inducea N. pole upon the free 1 is grmuided at 39, while the othertermiextremity of armature 17, While if armature 17 is in contact withcontact 2G current will tlouv Vtrom battery 22 through the helix otelectromagnet 18, armature 17, contact 26 and thence to the negativepole of battery 22, to induce a S. pole on the treo extremity ot'armature 17. Assume non,7 that armature 17 is at rest in contact withcontact 25 and that an alternating current of a delinite periodicity istraversing the helices oi magnet 15 and 1G to ground 2S, the positivemires ot the current Will induce a S. pole on the polo tace oil magnet16 and a N. pole on the pole face of magnet 15, While the negative wavesot current will induce a S. pole on the pole face of magnet 1.5 and a N.pole on the pole lace of magnet 16; thus, as armature 17 is in contactwith Contact 25 and is presenting a N. pole to the pole face otelcctromagnet 15 and as a positive i1npulse ot' current through thehelices of inagnets 15 and 1G produces a N. pole on inagnet 15 and a tl.pole on magnet 1G, armature 17 is attracted by magnet 1G to breakcontact With contact 25 and make contact With contact 26 1which changesthe direction of current through the helix of magnet 18 and therebyproduces a pole on the extremity oil armature 17. A negatire impulse of"current lfollowing the previous positive impulse through tle helicesoit' magnets and 16, induces a l pole on magnet 1G, thereby tending tohold armature 17 in contact With Contact 2e, While a positive impulse ofcurrent following the previous negative impulse, induces a S. pole onmagnet 1o and a C. pole on magnet 15, thereby attracting armature 17 tobreak connection from contact 2G and make connection with contact 25,which changes the jiiolarity ot its free extremity from S. back to N.and it is held in contact with contact until the next succeeding' piitire impulse through the helices ot magnets 15 and 1G. 1t thereforeobvious that a current oit a delinite periodicity through the helices ofmagnets 15 and 1G will produce in the helix of magnet 1S a current whichis in eiliect an alternating current of one halt the periodicit)Y of theoperating' current aiul, that this current of ono-halt periodicity ii;iinpres, ed on the printing elements in pairs iii shunt with the Windingof magnet 1S.

Referring nouv to the transmitter which is shown in diagram at the rightot Fig. 1, an alternating generator 38 is belted to any convenientsource ot' pou'er and is geared through shaft and spur gears 37 and 36with a conducting drum 33 which is rotatircly mounted between journalsby means ot the shaft 34. iti brush 30 may bear upon and make contactwith the surface of the drum and is connected to the line conductor 29.@ne terminal of the generator nal is connected to both the journal ofdrum and through an adjustable resistance 31 to line conductor 29. Thisallows of placing on the line 29 through the ground two intensities ofcurrent, one through the drum 33 and brush 30 and the other through theadjustable resistance 31; thev latter current 'value bein@l ad`ustablethrough a wide range b D b of intensity by means of the adjust-ableresistance 31. Assuming now the brush 30 to be out of contact with thedrum 33 and the generator 3S in operation, an alternating current may beplaced through the adjustable resist-ance 31 on the line 29 through thehelices of electromagnets 10, 15 and 16 to ground 2S, vof such a valuethat relay 100 may be adjusted through the adjustable resistance 20 tobe responsive thereto while the armature 12 opposite magnet 10 isunresponsive. This results in placing a potential alternating atone-half the periodicity of the line current on the pen faces 11, 22 33and 44 without moving the pen faces.

The drum 33 is provided with a median row of equally spaced insulatinginvaginating projections 331 which are so spaced with relation to theratio of speed of the drum 33 and generator 3S, that while the drum 33is rotated through an angular distance defined by that between any twoprojections 831 the generator 38 is placing on the drum 33, fourpositive potentials and four nega.- tive potentials and placing upon theline four complete current cycles. rlhus, if a transmitting tape 32 isprovided with a median row of -registry perforations and is placed onthe drum 33 so that its registry perforations engage the projections331, it will be possible by correctly spacing a perforation in the tapein relation to its longitudinal distance, fro-m any registryperforations, to send either a positive or a negative impulse fromgenerator 3S thro-ugh drum 33 and brush 30 to Aline conductor 29. Thisimpulse will be in phase with the current placed on the line throughadjustable resistance 31 and, as the impulse is placed on the linethrough a shunt of comparatively low resistance compared to theresistance 31, it will be of augmented energy as compared with theimpulses sent through resistance 31 to operate the polarized relay 100,and will thus energize magnet 10 to attract either end of armature 12,depending upon the polarity of the impulse. Armature 12 may lthus beoperated selectively to depress pen faces 11, 33, or 21, 44simultaneously into contact with the receiving tape 111 and as relay 1GOby its operation, as vhitherto explained, places a potential on the penfaces which reverse in direction twice while the line current potentialreverses four times,

it follows that both pairs of pens 11, 33 and 22, 41 may be successivelybrought into contact with tape line 111, while the potential impressionon their faces is either positive or negative.

If the anvil 11 be platinum coated and the tape 111 be impregnated withthe chemical compound previously mentioned, it is obvious that eitherpen faces of a pair in contact with the recording tape 111, may beimprinted thereon depending upon which pen face of a pair is at apositive potential with respect to the tape 111. Thus, assuming armature17 of relay 100 to be maintained in operationby an alternating currentfrom generator 8S, through resistance 81 to line conductor 29, if apositive impulse of current be sent through the brush 30 to lineconductor 29 it will operate armature 12 to depress pen fa-ces 11 and 33simultaneously into contact with tape 111 and pen 11 or 33 will be at apositive potential with respect to tape 111 depending upon whetherarmature 17 is at that instant in contact with contact 25 or 26respectively. Simi- Y larly, a negative impulse of current sent throughbrush 30 over line conductor 29 will cause armature 12 to depress penfaces and 4'* simultaneously into contact with tape 111 and either pen22 or 4L will be imprinted thereon dependent upon whether armature 1T isin contact with contact 25 or 26 respectively.

n Fig. 8 I have shown an enlarged view of the pen faces as they wouldappear were all of the types imprinted on a stationary recordingsurface, or it may be considered a plan view of the printing faces o-relements in their position in the receiver. Plans 11, 22 and 33 are inwidth each equal to the width of a complete normal character such as H.The width of a complete normal character is divided into eight arbitraryunits, each pen face being separated from its fellow by one of thesearbitrary units.

Referring now to Figs. 4 and 5, the phase relation that must existbetween the line current andthe current impressed on the pen faces, inorder to imprint legible characters with an arrangement of perforationsas shown in Fig. 4, is clearly indicated. face 4L is imprinted bysending a negative impulse from generator 3S through brush 30 over line29 through magnets 10, 16 and 15 to ground which causes armature 12 todepress pens 2 and 4 simultaneously into contact with tape 111 andassuming that armature 17 of relay 100 is at that instant in contactwith contact 26, current will flow from battery 22, through conductor23, lower blade of knife switch 42, conductor joining pens 3 and 4,spring of pen 4, pen face 44, tape 111, pen face 22, spring of pen 2,conductor joining pens 2 and 1, upper blade of lrnife switch 42,conductor 24, resistance 19,

armature 17, contact 26 to battery 22, theren.

Pen

by causing pen face 4t to assume a positive potential with respect totape 11l and causing thus its imprint thereon but not causing theimprint of pen face 22. Pen face 22 is imprinted by sending fromgenerator 38 through brush 30, line 29, helices of magnets 10, 16 and 15to ground, a negative impulse following the positive impulse immediatelysucceeding the negative impulse which caused the imprint of pen face 4t.As has hitherto been explained the positive impulse succeeding theprevious nee'ative impulse, has caused armature 17 to break con nectionfrom contact 2G and malte connection with contact rihus, as the negativeimpulse under discussion has caused armature 12 to again depress penfaces 22 and 44 simultaneously into contact with tape 111, current flowsfrom battery 21 through contact 25, armature 17, resistance 19,conductor 24, upper blade of knife switch 42, conductor oining pens land 2, spring of pen 2, pen face 22, tape 111, pen face 4*, spring ofpen 4, conductor joining pens 4 and 3,lower blade cf knife switch 42,conductor 23 to battery 21, thus causing pen face 22 to become positivewith respect to the tape 11'l and thereby causing its imprint thereon,but not causing' the imprint of pen face 44. 4Similarly two positiveimpulses separated by a negative impulse selectively cause theimprinting of pen faces 3' and 11.

Fig. 4 illustrates the relation between the operating perforations andthe registry perforations and shows the relation existing between theregistry perforations and all of the perforations necessary to operatethe printing pens in such sequence as to form legible characters. Thelongitudinal line 301 is an arbitrarily chosen contact line between thebrush 30 and the Crum 33 along which the pen-selective perforations arespaced. rifhe longitudiuffil line 332 is a median line along which theregistry perforations are spaced. The transverse lines 40, 30, 20, and10 are placed a distance apart equal to, or proportional to the unit ofwidth of the pen faces 11, 22, and dependent upon the ratio of the speedof the transmitting and receiving tapes. For the purpose of clearness inthis disclosure l will assume that this tape interval is equal to theunit of width of the pen faces, 11, 22 and as illustrated and that thetransmitting and receiving tapes move through commensurate distances inequal times. Thus, in order to selectively imprint any pen face it onlynecessary to place a perforation along the line 30l opposite a registryperforation, or one, two or three tape intervals removed therefrom, dependent upon the pen face which it is desired to imprint.

The manner of forming legible characters by the use of a tape perforatedin accordance with that illustrated in Fig. 6, is as follows: Assumingthat generator 38 is placing an alternating current on line 29, throughresistance 31, which is operating armature 17, at one-half the frequencyof the line current; that tape 32 perforated as shown in Fig. 6 is insuch a position on drum 33 that its registry perforations engage theprojections 33 and that the tape is being drawn under brush 30 by meansof the tra-in of gears 3G and 37 at a speed which is proportional to thegenerator speed as hitherto indicated, then a perforation along the line4O places through the brush 30 to line 29 an augmented negative impulsewhich imprints pen face 44 as previously disclosed and after a timeinterval of eight tape units a perforation along another line as 40allows another augmented negative impulse to flow through brush 30 toline 29 again imprinting pen ffice 4K1 which, as the receiving tape 11is considered to be moving through a commensurate distance from right tileft under pen face as indicated .in Fig. 3, while the transmitting tape32 is moving eight tape intervals, imprints the second imprint of penface 4A1 upon the receiving tape a distance away from the previousimprint of eight receiving tape units, or the width of a complete normalcharacter. After the tape has passed under the brush 30 a distance oftwo more tape intervals, a perforation along the line 20 allows anaugmented negative iinpulse to i'iow through brush 30 to line 2S),which, as before noted, follows an unintensii fied positive impulsethrough relay 10() which has changed the direction of current throughthe pen faces when in contact with the receiving tape 11 and thereforethe negative impulse under discussion results in imprinting pen face 22.As t-he two previous imprints of pen face 4Ak have before the imprintingof pen fa ce 22 moved under the type faces as viewed in Fig. 3, adistance of two units of width of a complete normal character, pen face22 is imprinted with its extremities abutting the two previous imprintsof pen face 44. After tape 32 has passed under brush 30 one more tapeinterval a pei'- foration along the line 10 allows of an augmentedpositive impulse beingsent through the brush 30 over line 29 whichimprints pen face 1 and as the tape 11. carrying the imprints of penfaces 44 and 22 has in the interim moved one unit of width of a normalcharacter to the left under the pen faces as viewed in Fig. 3 type facel is i1nprinted in such relation to the previous imprints that itsvertical leg registers with the upper half of the first imprint of penface 44, while the extremity of its horizontal leg abuts the latterimprint of pen face 44 to form the chartcter A. ln a similar manner allof the characters necessary to transmit intelligence in any languageusing the Roman alphabet may be transmitted and imprinted.

lll

It will be observed from the foregoing and from a study of Figs. 4 and 5t-hat a definite phase relation must at all times be maintained betweenthe line current and the current impressed on the pen faces through theoperat-ion of armature 17 of relay 100 in order to transmit intelligencewith the design of apparatus and circuits used and with thepredetermined arrangement of perforations in the tape with respect tothe registry perforations. This phase relation depends entirely upon theinitial or starting position of armature 17 with respect to its contactsand can be maintained by manually setting the armature 17 during itsperiods of rest in contact with the proper contact so that whengenerator 38 is started the phas-e relation of the line current andprinting current will always be in proper relation to each other toinsure the imprinting of the proper pen face for a predetermined spacingof the perforations with relation to their registry perforations. Thisnecessity for manually re-setting the armature 17 is obviated byproviding the double pole reversing switch 4t2 with which the operatormay reverse the current through the pairs of pen faces in contact withthe tape 1l. Thus, if a test tape perforated with a series ofperforations along the line 40, each spaced opposite a registryperforation to imprint a series of imprints from the pen face 44 bepreliminarily sent through transmitter before a message tape, thereceiving operator may by observing the resultant record, note whetherthe printing currents arein contact phase with the line currents, byobserving whether a series of equally spaced vertical lines are printedor whether the opposite pen of the pair, as 22, is producing a series ofshort lines resulting in a record having the form of a continuous medianline. If median line be received the operator reverses the position ofthe reversing switch 42 and a series of imprints from the pen face I4results upon the receiving tape, signifying to the operator that theapparatus is in a condition for receiving a message.

While I have illustrated and described only one embodiment of my device,it is to be clearly understood that I may malte numerous changes thereinwit-hout departing from the spirit or narrowing the scope of myinvention.

Having thus described my invention what I claim as new and desire tosecure by United States Letters Patent, is as follows:

l. In a printingtelegraph system, a plurality of printing elements aprinting surface, means responsive to current impulses of variantpolarities and predetermined intensit-y to effect the selectiveoperation into Contact with said printing surface of predeterminedgroups of said print-ing elements, and means responsive to currentimpulses of a predetermined polarity to effect the selective imprintingof any element of an operated group of said elements.

2. In a print-ing telegraph system, a printing surface, a relayresponsive to a cont-inuous series of impulses of alternating polarityand normal and maximum current intensity, and a plurality of printingelements operable selectively in predetermined groups into Contact withsaid printing surface of all the elements of a group by means of currentimpulses of variant polarities and of said maximum current intensity,said relay by its operation effecting the selective imprinting of anyelement of a group of said elements.

3. In a printing telegraph system a printing surface, a plurality ofprinting elements, an operating electromagnet responsive to currentimpulses of variant polarities and predetermined intensity to effect theengagement of said printing surface with said elements in predeterminedgroups, and a relay responsive to current impulses of predeterminedpolarity and lower intensity to effect the selective imprinting of anyelement of an operated group of said element-s.

4. In a printing telegraph system, a plurality of printing elements, arecord sheet, an operating electromagnet for said printing elementsresponsive to current impulses of variant polarity and predeterminedintensity to effect the selective operation of said elements inpredetermined groups to make Contact with said record sheet, and a relayresponsive to current impulses of predetermined polarity and variantintensity, to effect the selective imprinting of any element of a groupof said elements in contact with said record sheet.

5. In a printing telegraph system, a` relay responsive to continuousseries of impulses of predetermined polarity and normal and amplifiedcurrent intensity,` a plurality of printing elements, a record sheettherefor, said printing elements being operable selectively inpredetermined groups by means of current impulses of variant polarityand amplified intensity to malte Contact with said record sheet, saidrelay by its operation eiecting the selective imprinting on Vsaid recordsheet of any element of a group of said elements in contact therewith.

G. In a system of printing telegraphy, a printing surface, anelectro-magnetically polarized relay operated by current impulses ofpredetermined polarity, a plurality of printing 'elements operableselectively in predetermined groups by current impulses of variantpolarities and of `'augmented intensity to the impulses operating saidrelay, said relay by its operation effecting the selective imprinting ofany element of a group of said elements operated into contact with saidprinting surface.

7. In a printing telegraph system, a plurality of printing elements, arelay, said relay being operable to place upon said printing elementscurrent impulses of variant polarity and of a predetermined frequency,said printing elements being operable lectively in predetermined groupsby means of current impulses of Variant polarity and of augmentedintensity to the currents operating said relay.

8. in a printing' telegraph system, a receiving station, atransn'iitting station and a line conductor and ground connecting them,means at said transmitting' station for impressing upon said conductorand ground an alternating current of a definite frequency and Variantintensity; a relay at said receiving station operated by saidalternating current, a printing surface, a plurality of printingelements, means for utilizing one Value of the intensity of saidalternating current to effect the selection of a group of said printingelements, and for moving them into engagement with said printingsurface, and means for utilis'ng the ope z tion of said relay to effectthe selective imprinting of any one of an operated group of saidelements.

9. ln a printing telegraph system, a transmitter, a receiver and a lineconnecting them, said transmitter being operable to place on said linean alternating current having normal and amplified current values; aplurality of printing el-ements, an operating magnet therefor, and arelay operable by impulses of said alternating current of apredetermined polarity and normal current value to impress on saidprinting elements, current impulses of one-half the frequency of saidoperating alternating current, said printing elements being operableselectively in predetermined groups through said operating magnet bymeans of impulses of said alteriniting` current of variant polarity andof said amplified current Value.

10. In a printing telegraph system, a receiving station, a transmitting`station and a line conductor and ground connecting them, means at saidtransmitting station for impressing upon said conductor and ground,

an alternating current of a definite frequency, and intensity, andcurrent impulses of variant polarity and augmented intensity in phasewith said alternating current; a relay at said receiving station,operated by said alternating current, a plurality of printing elements,means for utilizing said current impulses of variant polarities andaugmented intensity to effect the selection of a predetermined group ofsaid printing elements, means for utilizing the operation of said relayto effect the imprinting on a receiving surface of any of said elementsof said selected group.

ll. ln a printing telegraph system, the combination with a sendingstation, a receiving station, and a connecting line consisting of onewire and ground, of two groups of printing characters and a receivingsurface at the receiving station, a source of alternating current, andmeans controlled from the sending station for primarily se lecting agroup of characters and moving same into contact with the receiving surface, and secondarily selecting a desired character from the selectedgroup byv impulses fiowing over said connecting line.

l2. A source of alternating current, a second alternating currentcontrolled by the first so that it will have oneehalf the frequency ofthe first, a series of four printing characters, and means controlled bythe joint action of the two currents for printing' said charactersselectively.

13. The combination with four printing` characters, of means forproducing two alternating currents, means operating through one currentfor controlling the other so that the frequencies of the two currentswill be to each other as two to one, and means operating through theconjoint action of the two currents for printing said type selectively.

Signed by me at Toronto, county of York, and hrovince of Ontario, in thepresence of two witnesses.

CHARLES G. ASHLEY.

l/Vitnesses VWM. J. HERDMAN, H. M. CHRISTMAN.

Copies of this patent may be obtained for five cents each, by addressingthe Gommssioner of Yatents, Washington, D. C.

